Deyice foe fokming and deciphering secbet communications



(No Mode1.

M. A. WIER. DEVICE EUR FOEMING AND'DECIPHERINC SECRET COMMUNICATIONS.

No. 449,723. Patented Apr. 7, 1891.

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Nrrhn STATES PATENT OFFICE.

MARSHALL A. VIER, OF LONDON, ENGLAND.

DEVlCE FOR FORMING AND DECIPHERING SECRET COMMUNICATIONS.

SPEQIFICATION forming part of Letters Patent No. 449,723, dated April 7, 1891. Application led September 30, 1890. Serial No. 366,706. (No model.)

To all whom it may concern:

Befit known that I, MARSHALL ARTHUR VIER, engineer, a subject of the Queen of Great Britain, and residing at 3 Palace Grove, Upper Norwood, London, in the county of Surrey and Kingdom of Great Britain, have invented a new or Improved Method of Forming and Deciphering Secret Communications, of which the following is a specification.

This invention relates toanew orimproved device for forming and deciphering secret t communications, which, besides being applicable to the formation and decipheringof cryptographic or code messages in general, for transmission by telegraph or otherwise, is specially applicable for use in connection with the improved apparatus for producing; and deeiphering 'secret writing, for which I applied for a patent in the United States on August 22, 1888, Serial No. 283,461. For this purpose I employ what I call a bi-letter code, which consists of special combinations of couplets of letters (in combination, or not, with what I call distinguishing letters to represent the various words or groups of words of the intended message. For example, the letters A A may represent the word abandon, the letters A B the word abate, the letters B A against, and so on, or each pair or couplet of letters may represent a complete sentence or group of words instead of a single word. It will be seen that by the employment of these combinations twenty-six times twenty-siX-equal to six hundred and seventy-six words or groups of words-can be represented if the entire alphabet is employed; but as I employ certain letterssay K V lV Z, for example-exclusively as distinguishingletters, as will be hereinafter more fully explained, say twentytwo letters only are available for use in the construction of couplets, thus giving twentytwo timesV twenty-two, or four hundred and eighty-four couplets. As four hundred and eighty-four Words or groups of words would be ordinarily insufficient for the purpose of constructing cryptographs or secret communications, I, after having applied Words or groups of words to the first four hundred and eighty-four couplets, insert a distinguishing letter-K, for example-between the two letters forming the next set of four hundred and eighty-four complets A K A, A K I3, the., and apply words or groups of words to these couplets, and so on for each of the four distinguishing letters; and I thus obtain a total of iive times four hundred and eighty-four, equal to two thousand four hundred and twenty couplet combinations, representing the same number of words or groups of words,which is generally sufiicient for all practical purposes. A cryptograph or secret communication, when written out in these couplets, simply consists of a series of letters, which appear to have been taken indiscriminately, thus F J O PL K S RVERBAZT; but it the communication is sent by telegraph it will be received divided into groups of letters, according to the particular rules of the telegraph companies that may be in force at the time with regard to cipher messages. I will assume it to be five letters to a group. In such a case the message will be received in this form: F J O P L, K S R XV E, R .B A ZT. The receiver would divide this message into couplets, taking care to regard either ot' the letters K, V, 7, or Z, wherever it occurs, as forming no part of the couplet, but only as distinguishing the part of the code to which the couplets formed by the letters on either side of such distinguishingletters belong. He would accordingly write out the message in the following way, viz: F J, O P, Lk S, RW E, R B, AZ T, and he would then find from that part ot' his code not marked with a distinguishing letter the meaning of the couplets F J, O P, R B, which have no distinguishing letters, and from those parts of his code marked K, XV, and Z the meaning of the couplets L S, R E, and A T in those respective parts. The formation or construction of a cryptograph or secret message is effected by the reverse process.

For the purpose of facilitating the formation and deciphering ot' cryp tographic or code messages composed of arbitrary figures or letters, or combinations thereof representing intelligible words, it has heretofore been customary to arrange such arbitrary Iigures or letters and their corresponding intelligible words in printed or written parallel columns arranged bookwise and to prepare or decipher IOO of one form of the apparatus; Fig. 2, a section of same on line l 2 of Fig. l, and Fig. 3 a partial plan of a slightly-different arrangement of such apparatus.

Referring to Figs. 1 and 2, A is a sheet, board, or tablet having a number of divisions marked on the upper surface thereof, formed by lines drawn at right angles to each other or otherwise. In each of these divisions is written or printed a couplet of letters. movable sheet, board, or tablet B, correspond ing in size to the base-board or tablet A, is adapted to be placed over the latter or to be removed therefrom at pleasure.

The upper surface of the movable board or tablet B is divided into divisions by lines exactly corresponding to those marked on the base-board or tablet A, and the divisions on the movable board or tablet B have written or printed in them the word corresponding to placed over the base-board the divisions on' the former will stand exactly over those on the latter, so that any given word on the movable board will stand immediately over its correspondin g couplet on the base-board below. In the example shown in the drawings the board or tablet B is arranged to slide over the sur` face of the board or tablet A, being guided in the grooves C of the lateral guides D.

At one side or end of the base-board is pivoted, as at E, for example, an arm F of sufiicient length to sweep over the entire surface of the base-board on which the divisions are marked. On this arm is arranged a sliding pointer G, which can be adjusted into any position longitudinally on the said arm.

Assuming now that it is desired to prepare a cryptographic orsecret communication, the movable board or tablet B is slid in until the edge B comes against the stop A', so that the first column of words on the movable board B, commencing with the woid abandon, stands over the Iirst column of couplets on the base-board A, commencing with the couplet A A. The first word of the intended cryptogram is then found on the movable board B, and the arm F is moved round its pivot E nntil it stands over that word. The pointer G is then slid along the arm F till it also comes over the said Word. The movable board is then drawn out from under the arm F and pointer G, leaving themiinmoved. Vhen the movable board is drawn out beyond the pointer G-as in the position shownin the drawings,

-along the edge A=i Ait.

for example-the pointer G remains standing over the couplet of letters corresponding to the Word to which it was set on the movable board B. This couplet is written down by the operator and forms the first element of thedesired cryptograph or secret communication. The movable boardB is then replaced, the next word of the communication is found thereon, the arm and pointer adjusted ovei it, the movable board again withdrawn, and the second couplet will be found under the pointer, and so on for each word of the intended communication.

By having several separate boards si'milar to B, but each having a different series of words written in its divisions, and each having a distinguishing letter, such. as K, Y, W, or Z, as above mentioned, applied to it, the Whole of the two thousand four hundred and twenty words or combinations of words, as above described, can be utilized by placing the distinguishingA letter K, V, WV, or Z, corresponding to the board used, between the letters of the couplet found on the base-board A. The deciphering of a cryptogram is effected by proceeding in a reverse order. Instead of a pivoted arm, abar may be arranged to slide parallel to itself over the aforesaid boards, the pointer being arranged to slide longitudinally on such bar.

Fig. 3 of the drawings shows aslightlydifferent arrangement of the apparatus. A is a transparent sheet of celluloid or other suitable transparent material, on which are printed or otherwise formed in suitably-arranged divisions the four hundred and eighty-four couplets,'for example, liereiiibefore referred to. This sheet A is capable of being raised up and turned over, like the leaf of a book, Five other sheets or boards, (preferably opaque,) the first of which need have no distinguishing mark, but the other four of which may be marked, respectively, K V W Z, as before explained, are arranged bookwise below the transparent sheet A. Each of these sheets or boards is arranged to turn over, like the leaf of a book, along their edges B* B*, and have written or printed on them words in positions corresponding to the divisions on the transparent sheet A, so that when the latter is laid over one of the opaque sheets the words on the latter appear through the divisions on the former, as shown in the drawings. For example, the Word abactus on the opaque sheet next below the transparent sheet A is seen in the division containing the couplet A A on the transparent sheet A. In composing a cryptograph or secret communication each required Word is first found on one of the five sheets or boards, the sheets that happen to be above it being turned over out of the way on their edges B* Bi, the transparent sheetA is placed over the sheet where the said word occurs, and the couplet of letters which appears on the transparent sheet above the said word is written down by the operator, and if the said IIO word occurs on the sheet marked K, for example, he inserts the distinguishing letter K between the two letters of the couplet, which indicates to the receiver that the corresponding word is to be found on the K sheet under the particular couplet on the transparent sheet A.

The words shown on the movable board in Fig. 1 are intelligible words, and the secret communication may be translated by its aid directly; but it is obvious that instead of intelligible words code-Words may be employed, which would require the use of a code-book to effect their translation to or from the couplet ciphers. Similarly the words shown in Fig. 3 are code-words; but they may be intelligible words, if preferred.

I employ distinguishing letters, as above explained, instead of distinguishing numbers, for the reason that combinations of cipher letters and numerals are not at present allowed by the telegraph companies to be used; but if and when numbers are allowed to be used in combination with cipher letters, numerals may be used instead of letters to distinguish the sheets or tables of Words with the result that the Whole twentysix letters of the alphabet may be used to form couplets giving twenty-six times twenty-six equal six hundred and seventy-six couplets instead of four hundred and eighty-four, when four of the letters are reserved as distinguishing letters, and as any number of numerals might be used the number of words or ciphers that could be employed is pratically unlimited.

It will be understood that the communication consisting of couplets, as above described, after being arranged or set up, maybe transposed by the aid of the cryptographic typewriting system described in the specification filed with my before-mentioned application 'for patent in such a manner as to render itimpossible of interpretation except by a person having the key.

It is obvious that in the apparatus shown in Figs. 1 and 2 the couplets might be written or printed on the movable board B, and the words on the base-board A; but in that case several base-boards would be required to one movable board, which would not be so convenient an arrangement as that shown. It is also obvious that in the apparatus shown in Fig. 3 the words may be written or printed on several transparent sheets, and the couplets on a opaque sheet which can be placed under any one of the transparent sheets.

It will be understood that Figs. 1 and 2 show only one corner of each apparatus, the remainder being obviously of similar arrangement, and that in Fig. 3 each of the sheets is shown broken away to expose a part of the sheet next below it.

I claiml. A movable sheet or board containing words to be translated into cryptograms, in combination with a sheet or board containing cryptographic characters,^the said sheets or boards being superposed and having each word arranged directly under or over each cryptographic sign or set of signs, substantially as set forth.

2. A movable sheet or board containing Words to be translated into cryptograms, in combination with a sheet or board containing cryptographic characters, and a movable pointer arranged and adapted to indicate any one of said words, the said sheets being su perposed and each word being arranged directly under or over the corresponding cryptographic character or combination,substan tially as set forth.

In testimony that I claim the foregoing as my inventionI have signed my name in presence of two subscribing witnesses.

MARSHALL A. IVIER.

Witnesses:

STEPHEN EDWARD GUNYON,

115 Cannon, Street, London.. WILLIAM ANDERSON SMITH,

73 Sydncr Road, London, N. 

